When you are told to drink your milk, eat your greens, or go out in the morning sun, you should do it. Any one of these activities will definitely help you with your daily allowances of calcium and vitamin D (choecalciferol). As you may know, calcium is responsible for strong bones and teeth; proper nerve function; efficient secretion of enzymes and hormones; and good contraction of muscles. Vitamin D makes the effective absorption of calcium in your body. It prevents cancer. It is also important for maintaining mental, bone, and cardiovascular health.